Changes between Initial Version and Version 1 of ModelSyntaxChangeInstructions

Timestamp:

Aug 25, 2005, 3:02:13 PM (20 years ago)

Author:

Jacob

Comment:

--

ModelSyntaxChangeInstructions

@@ +1 @@
+== Django model syntax change ==
+
+As of ____, Django's model syntax has changed. If you're using models that use old (pre-____) syntax, you'll need to convert them according to the instructions on ModelSyntaxChangeInstructions.
+
+=== What changed ===
+
+ * Fields are now attributes of the model class, rather than members of a {{{fields}}} list.
+ * Meta information (anything that's NOT a field, such as {{{ordering}}}, {{{admin}}}, {{{unique_together}}}, etc.) now goes in an inner class, called {{{META}}} (note the all caps). This class doesn't have a parent class.
+ * Each field is required to have an explicit name -- even {{{ForeignKey}}}s, {{{ManyToManyField}}}s and {{{OneToOneFields}}}. This solves the problem of "How do I refer to my field from within admin.fields?"
+ * {{{rel_name}}} is no longer used for {{{ForeignKey}}}s. If your model has more than one {{{ForeignKey}}} to the same foreign model, differentiate the fields using the field name, not {{{rel_name}}}. See [http://www.djangoproject.com/documentation/models/m2o_recursive2/ Relating a model to another model more than once] for an example.
+ * {{{rel_name}}} is no longer used for {{{ManyToManyField}}}s. If your model has more than one {{{ManyToManyField}}} to the same foreign model, differentiate the fields using the field name, not {{{rel_name}}}. Also, give both of the {{{ManyToManyField}}}s a {{{singular}}} attribute, which defines the name of the related object in singular format. (This is an obscure case, but it's included here for completeness.)
+
+=== Examples ===
+
+Old syntax example:
+
+{{{
+#!python
+class Foo(meta.Model):
+    fields = (
+        meta.CharField('first_name', maxlength=30),
+        meta.CharField('last_name', maxlength=30),
+        meta.ForeignKey(Bar),
+        meta.ManyToManyField(Sites),
+    )
+    ordering = ('-bar_id',)
+    admin = meta.Admin(
+        fields = (
+            (None, {'fields': ('first_name', 'last_name', 'bar_id', 'sites')}),
+        ),
+    )
+}}}
+
+New syntax example:
+
+{{{
+#!python
+class Foo(meta.Model):
+    first_name = meta.CharField('first_name', maxlength=30)
+    last_name = meta.CharField('last_name', maxlength=30)
+    bar = meta.ForeignKey(Bar)
+    sites = meta.ManyToManyField(Sites)
+    class META:
+        ordering = ('-bar',)
+        admin = meta.Admin(
+            fields = (
+                (None, {'fields': ('first_name', 'last_name', 'bar', 'sites')}),
+            ),
+        )
+}}}
+
+Notes:
+
+ * {{{bar}}} and {{{sites}}} now have explicit names, and {{{admin.fields}}} was changed to use {{{bar}}} instead of {{{bar_id}}}.
+ * {{{ordering}}} was also changed to use the explicit name {{{bar}}} instead of {{{bar_id}}}.
+ * Don't forget to remove the commas after each {{{Field}}}, because they're class attributes instead of list elements now.